Human diseases transmitted by mosquitoes have serious negative impacts on populations in tropical countries and also affect populations in temperate regions (for example, the recent emergence of West Nile virus in North America). Anopheles gambiae is a major vector of malaria parasites in sub-Saharan Africa. Better understanding of the biology of A. gambiae may lead to improved strategies for disrupting malaria transmission and for controlling other mosquito vectors of human diseases. The recent release of the DNA sequence of the A. gambiae genome has been a major achievement that should make possible rapid progress in molecular studies of the function of gene products in this mosquito. This proposal for an Investigator-Initiated Small Research Grant is to initiate pilot studies on the biochemistry of two groups of proteins in An. gambiae: serpins and laccases. Serpins are serine protease inhibitors, which have potential to regulate insect immune responses. However, their functions in mosquitoes have not yet been defined. Laccases are copper oxidases that can oxidize diphenols as well as other types of substrates. Laccases may function in insect cuticle sclerotization or immunity, but they have been the subject of little previous biochemical study. The aims of this project are to obtain full-length cDNA clones corresponding to the five laccase-like genes and a selected group of the 14 serpin genes from An. gambiae and to use these cDNAs as probes to study expression of the genes and for production of recombinant proteins for initiation of biochemical studies. These aims are intended to produce preliminary results to support future more extensive proposals on An. gambiae serpins and laccases. This project will be a start toward development of a new research area for the PI (mosquito biochemistry) that will build from his experience in biochemistry of other groups of insects.